The present invention is found in the field of networked systems such as computer networks or bus systems. A computer network is a combination of different technical, primarily stand-alone electronic systems, such as computers, sensors, actuators, functional components, etc., hereinafter referred to in brief as nodes of network nodes, the possibility of central management of nodes of the computer network being of particular importance in this case.
A conventional and advantageous architecture for centrally organised management of the nodes is the so-called master-slave architecture, which is a form of hierarchical management of access to a common resource, such as a memory. In a computer network constructed in a master-slave architecture, one node acts as master and all other node are the slaves. Only the master has the right to access the common resource without being prompted. These masters thus act as control devices for controlling the other network nodes of the same computer network, which operate as slaves. The present invention and the problem on which it is based are described below with reference to a master-slave computer network in an aircraft, without limiting the invention to that effect.
In order to control the slaves in a master-slave computer network, the master produces control commands individually for all slaves which it is to control and transmits these control commands to the corresponding slaves, usually in a fixed time-slot pattern. In most master-slave computer networks, a single master controls all available slaves. A network of this type is also referred to as a single-master network.
In addition to these control tasks for controlling the slaves, a master usually also performs further computing tasks, for example reading in, storing and monitoring sensor data, producing real-time data, etc. The computing load of the master and thus the operability of the master-slave computer network thus depend substantially on the computing power of the master, the computing and control tasks thereof and the number of slaves which must be controlled by the master. This is not critical when there are a low number of slaves. However, it is problematic when the master-slave computer network comprises a plurality of 1000 or more slaves which are each controlled by the same master. Computer networks of this type comprising over 1000 slaves are used, for example, in an aircraft in the cabin networking, such as the cabin lighting, in-flight management, etc. In this case, the computing load of the master increases in accordance with the number of slaves it controls.
A master in an extensive master-slave computer network of this type must, in the time-slot pattern preset for said master, produce the control commands for all the slaves and transmit said control commands to the respective slaves. A very high computational effort by the master is required to produce and transmit the control commands. Depending on priority, the master cannot perform further computing tasks during this time or the slaves are controlled with a correspondingly time delay.
In this case, the computational effort of producing the control commands scales approximately linearly with the number of slaves to be controlled by the master. If a master requires, for example, 5 ms to produce a control command for one slave, the master thus already requires approximately 500 ms to produce the control commands for 100 slaves and even 5 s for 1000 slaves.
If the master of a network does not have sufficient computing resources to perform additional calculations in a preset time in addition to producing the control commands, this inevitably leads to delayed reactions of the master, which causes, for example, loss of comfort when controlling nodes of a computer network in an aircraft.
Therefore, in order still to be able to perform further computing tasks in parallel with the production of the control commands for the slaves, a plurality of computing means are usually used which, for example, perform the necessary calculations independently of the master. However, the use of further computing means increases the complexity and in particular also the cost of a computer network. In addition, the installation effort, the maintenance effort and the associated costs also increase as a result.